This paper studies the impact of an unfunded social security system on the distribution of altruistic transfers in a framework where savings are due to both life cycle and random altruistic motivations. We show that the effect of social security on the distribution of these transfers depends crucially on the strength of the bequest motive in explaining savings behaviour. We measure this strength by the expected weight that individuals attach to the utility of future generations. On the one hand, if the bequest motive is strong, then an increase in the social security tax raises the bequests left by altruistic parents. On the other hand, when the importance of altruism in motivating savings is sufficiently low, the increase in the social security tax could result in a reduction of the bequests left by altruistic parents under some conditions on the attitude of individuals toward risk and on the relative returns associated with private saving and social security. Some implications concerning the transitional effects of introducing an unfunded social security scheme are also discussed.

Much of the existing literature on social security has taken the extreme assumption that individuals have little or no altruism; this paper takes an opposite assumption that there is full two-sided altruism. When households insure members that belong to the same family line, privatizing social security can gain public support. In our benchmark model calibrated to the U.S. economy, privatization without compensation is favoured by 52% of the population. If social security participants are fully compensated for their contributions, and the transition to privatization is financed by a combination of debt and a consumption tax, 58% experience a welfare gain. These gains and the resulting public support for social security reform depend critically on a flexible labour market. If the labour supply elasticity is low, then support for privatization disappears. Copyright 2007, Wiley-Blackwell.

We build a heterogeneous agents life cycle model that captures a large number of salient features of individual male labour supply over the life cycle, by education, both along the intensive and extensive margins. The model provides an aggregation theory of individual labour supply, firmly grounded on individual-level micro-evidence, and is used to study the aggregate labour supply responses to changes in the economic environment. We find that the aggregate labour supply elasticity to a transitory wage shock is 1.75, with the extensive margin accounting for 62% of the response. Furthermore, we find that the aggregate labour supply elasticity to a permanent-compensated wage change is 0.44.